[Technical principles of solid tridimensional modeling with computerized tomography for the study of maxillofacial diseases].

Abstract

3DCT allows the solid modeling of body structures from contiguous slices. The 3D images are free to rotate on the x, y, and z axes. It is possible to evidentiate structures with various densities by means of threshold operators, which allow a 3D model of both soft tissues and bones to be obtained. Shading operations allow image quality to be improved by varying the elementary units to surface units ratio. Implemented 3D rendering reduces the spatial edges by means of anti-aliasing functions. The 3D images allow the study of the complexity of maxillofacial bony structures, and they are especially useful in both surgical planning and in postoperative follow-up. We studied 58 patients with maxillofacial diseases (34 traumatic, 14 malformations, 4 dysplastic, and 6 neoplastic). In most cases (96.5%), we obtained high-quality images, which allowed both the site and the extension of the lesions to be evaluated, together with their relationships to adjacent structures. In 65% of traumatic cases, the 4 basic views thoroughly demonstrated lesion spread, while in the extant 35% of cases cutting operations and rotatory translations were necessary. In all malformation cases a clear visualization of somatic asymmetries was obtained. In both dysplastic and neoplastic cases, the best lesion evidence was obtained in superficial lesions with cortical bone involvement. This technique was always easy and quick to perform, with no need for supplemental dose exposure to the patient.